Welding and Fabrication Eng. Craft Practice 2, May/June 2015

Question 1

1. (a) Explain the following properties of metals:

(i) hardness;

(ii) toughness;

(iii) strength.

(b) (i) List the three types of gas flames.

(ii) List the composition of each flame.  

Observation

This question did not pose much problem to most of the candidates who attempted it as they were able to provide the required responses. However, some of the candidates gave same explanation for strength and hardness and some interchanged their explanations.
The required responses to this part of the question are given below.
(i)         Hardness is the ability of a metal to withstand wear, scratching or indentation.                                                         (ii)         Toughness is the ability of a metal to withstand sudden heavy load without fracture or absorb a great deal of energy before it fractures.                                                                                                          

    (iii)        Strength is the ability of a metal to resist deformation without rupture or failure.